The present invention relates to temporary electrical contacts between electronic components and, more particularly, to very small compliant electrical contacts for circuit board and chip testing.
Compliant electrical contacts or spring probes are generally known in the art. The purpose of these electrical contacts is to provide a temporary or separable electrical interconnection between two electrical conductors. Accordingly, there is no permanent mechanical interconnection between the electrical conductors by such means of soldering or bonding. In order to make a good electrical contact between the probe and the device under test, the probe must include a spring or other resilient and flexible structure. Typically, some form of a spring is used to make the flexible or compliant contact between the components.
Compliant electrical contacts also compensate for irregularities in the contact surface of the device under test. The spring applies a constant contact force at the probe tip to provide a consistent electrical contact.
A typical spring probe consists of a plunger, a spring and a barrel which houses the plunger and spring. The plunger slides within the barrel and is biased outwardly from the barrel by the spring. A spring probe may include a second plunger to provide a probe with two tips which are biased outwardly from each end of the barrel by the spring.
One problem with these types of probes is they have multiple parts that must be assembled together. These probes may fail due to excessive wear between contacting parts. Additionally, these probes are not well suited to high-density application needs of very small integrated circuits of a device under test.